"Grey's Anatomy" season 11 spoilers for episode 18 titled, "When I Grow Up," teases that the story arc would center on Callie Torres (Sarah Ramirez) and Stephanie Edwards (Jerikka Hinton).

According to "Grey's Anatomy" season 11 spoilers from Ecumerical News, episode 18, "When I Grow Up," follows Callie as she operates on a police captain, who has suffered great trauma to his leg. The police captain, Jack, is played by "Southland" alum Kevin Alejandro. Although he is slated for only a guest role to last just one episode, his part on the show may evolve into a recurring one.

The episode also follows a group of children as they embark on their school field trip to the Grey Sloan Memorial Hospital. However, things take a dark turn when they witness two police officers getting wheeled into the emergency room in order to get treatment for their injuries.

Stephanie develops a crush on one of the chaperones on the field trip. Taylor John Smith of "Hawaii Five-O" fame plays the said chaperon in the latest episode of the show. It's said that fans of Grey's Anatomy should expect a lot of drama from Stephanie in episode 18.

According to its promotional video, "When I Grow Up" also sees the return of Derek Shepherd (Patrick Dempsey) or as he is more popularly known, "McDreamy." The video also shows that he is planning to create a commotion at the Grey Sloan Memorial Hospital after returning from his job in Washington, D.C. Fans can only expect more dramatic twists and turns on the forthcoming "Grey's Anatomy" episodes brought by his return.

Check out the promotional video for "Grey's Anatomy" season 11, episode 18, "When I Group Up" below.

"Grey's Anatomy" season 11, episode 18 "When I Grow Up" airs April 2, Thursday at 8pm ET on ABC.

Tune in for more "Grey's Anatomy" season 11 spoilers, cast updates and recaps.